com.softsynth.jmsl.score.transcribe
Class MeasureExtractor

java.lang.Object
  com.softsynth.jmsl.score.transcribe.MeasureExtractor

public class MeasureExtractor
extends java.lang.Object

Given a source MusicShape where dimension 0 stores absolute times for events (as opposed to relative durations), pull out a subset of the MusicShape that fall within a measure's time window. Assumes ontimes have already been adjusted for tempo, so that 1.0=quarter note. Resulting extracted MusicShape contains on-times normalized relative to start time of measure.
Note: don't expect the on-time of the first element to be 0, since it may not have landed on a measure boundary.

Author:

Nick Didkovsky Feb 3, 2002 , (c) 2002 Nick Didkovsky, All Rights reserved.

Constructor Summary

MeasureExtractor()

Method Summary

double	extract() Pull out a subrange of the source shape.
MusicShape	getExtractedMusicShape()
double	getStartTime()
static void	main(java.lang.String[] args) Test a few simple cases.
void	setSourceShape(MusicShape s) This is the MusicShape from which one measure's worth of elements are extracted
void	setStartTime(double startTime) Set the start time within the source shape to begin pulling events
void	setTempo(Tempo tempo) Used to scale the calculate time span within which elements are extracted
void	setTimeSignature(TimeSignature ts) Used to calculate time span within which elements are extracted

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MeasureExtractor

public MeasureExtractor()

Method Detail

setSourceShape

public void setSourceShape(MusicShape s)

This is the MusicShape from which one measure's worth of elements are extracted

setTimeSignature

public void setTimeSignature(TimeSignature ts)

Used to calculate time span within which elements are extracted

setTempo

public void setTempo(Tempo tempo)

Used to scale the calculate time span within which elements are extracted

setStartTime

public void setStartTime(double startTime)

Set the start time within the source shape to begin pulling events

getStartTime

public double getStartTime()

extract

public double extract()
               throws TimeWindowNotFoundException

Pull out a subrange of the source shape. Call getExtractedMusicShape() to retrieve the resulting MusicShape. See docs for main() for an example of a loop which processes an entire source shape.

Returns:

the absolute end time of the measure's time span.

Throws:

TimeWindowNotFoundException - if all elements in the source music shape are earlier than the requested start time.

getExtractedMusicShape

public MusicShape getExtractedMusicShape()

Returns:

the MusicShape extracted by the most recent call to extract()

main

public static void main(java.lang.String[] args)

Test a few simple cases. Note a simple loop structure that keeps extracting from a MusicShape until done might look like this:

            boolean keepExtracting = true;
            while(keepExtracting) {
                try {
                    extractor.setTimeSignature(new TimeSignature(3, 4));
                    extractor.setStartTime(extractor.extract());
                    MusicShape extractedMeasure = extractor.getExtractedMusicShape();
                    extractedMeasure.print();
                }

                catch (TimeWindowNotFoundException e) {
                    System.out.println("Done");
                    keepExtracting = false;
                }
            }